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✏️ Editing: gd_rotate.c

#include "gd.h"

#include "gd_intern.h"
#include <math.h>

/*
 * Rotate function Added on 2003/12
 * by Pierre-Alain Joye (pierre@php.net)
 **/
/* Begin rotate function */
#ifdef ROTATE_PI
#undef ROTATE_PI
#endif /* ROTATE_PI */

#define ROTATE_DEG2RAD  3.1415926535897932384626433832795/180
void gdImageSkewX (gdImagePtr dst, gdImagePtr src, int uRow, int iOffset, double dWeight, int clrBack, int ignoretransparent)
{
	typedef int (*FuncPtr)(gdImagePtr, int, int);
	int i, r, g, b, a, clrBackR, clrBackG, clrBackB, clrBackA;
	FuncPtr f;

int pxlOldLeft, pxlLeft=0, pxlSrc;

/* Keep clrBack as color index if required */
	if (src->trueColor) {
		pxlOldLeft = clrBack;
		f = gdImageGetTrueColorPixel;
	} else {
		pxlOldLeft = clrBack;
		clrBackR = gdImageRed(src, clrBack);
		clrBackG = gdImageGreen(src, clrBack);
		clrBackB = gdImageBlue(src, clrBack);
		clrBackA = gdImageAlpha(src, clrBack);
		clrBack =  gdTrueColorAlpha(clrBackR, clrBackG, clrBackB, clrBackA);
		f = gdImageGetPixel;
	}

for (i = 0; i < iOffset; i++) {
		gdImageSetPixel (dst, i, uRow, clrBack);
	}

if (i < dst->sx) {
		gdImageSetPixel (dst, i, uRow, clrBack);
	}

for (i = 0; i < src->sx; i++) {
		pxlSrc = f (src,i,uRow);

r = (int)(gdImageRed(src,pxlSrc) * dWeight);
		g = (int)(gdImageGreen(src,pxlSrc) * dWeight);
		b = (int)(gdImageBlue(src,pxlSrc) * dWeight);
		a = (int)(gdImageAlpha(src,pxlSrc) * dWeight);

pxlLeft = gdImageColorAllocateAlpha(src, r, g, b, a);

if (pxlLeft == -1) {
			pxlLeft = gdImageColorClosestAlpha(src, r, g, b, a);
		}

r = gdImageRed(src,pxlSrc) - (gdImageRed(src,pxlLeft) - gdImageRed(src,pxlOldLeft));
		g = gdImageGreen(src,pxlSrc) - (gdImageGreen(src,pxlLeft) - gdImageGreen(src,pxlOldLeft));
		b = gdImageBlue(src,pxlSrc) - (gdImageBlue(src,pxlLeft) - gdImageBlue(src,pxlOldLeft));
		a = gdImageAlpha(src,pxlSrc) - (gdImageAlpha(src,pxlLeft) - gdImageAlpha(src,pxlOldLeft));

if (r>255) {
        	r = 255;
        }

if (g>255) {
			g = 255;
		}

if (b>255) {
			b = 255;
		}

if (a>127) {
			a = 127;
		}

if (ignoretransparent && pxlSrc == dst->transparent) {
			pxlSrc = dst->transparent;
		} else {
			pxlSrc = gdImageColorAllocateAlpha(dst, r, g, b, a);

if (pxlSrc == -1) {
				pxlSrc = gdImageColorClosestAlpha(dst, r, g, b, a);
			}
		}

if ((i + iOffset >= 0) && (i + iOffset < dst->sx)) {
			gdImageSetPixel (dst, i+iOffset, uRow,  pxlSrc);
		}

pxlOldLeft = pxlLeft;
	}

i += iOffset;

if (i < dst->sx) {
		gdImageSetPixel (dst, i, uRow, pxlLeft);
	}

gdImageSetPixel (dst, iOffset, uRow, clrBack);

i--;

while (++i < dst->sx) {
		gdImageSetPixel (dst, i, uRow, clrBack);
	}
}

void gdImageSkewY (gdImagePtr dst, gdImagePtr src, int uCol, int iOffset, double dWeight, int clrBack, int ignoretransparent)
{
	typedef int (*FuncPtr)(gdImagePtr, int, int);
	int i, iYPos=0, r, g, b, a;
	FuncPtr f;
	int pxlOldLeft, pxlLeft=0, pxlSrc;

if (src->trueColor) {
		f = gdImageGetTrueColorPixel;
	} else {
		f = gdImageGetPixel;
	}

for (i = 0; i<=iOffset; i++) {
		gdImageSetPixel (dst, uCol, i, clrBack);
	}
	r = (int)((double)gdImageRed(src,clrBack) * dWeight);
	g = (int)((double)gdImageGreen(src,clrBack) * dWeight);
	b = (int)((double)gdImageBlue(src,clrBack) * dWeight);
	a = (int)((double)gdImageAlpha(src,clrBack) * dWeight);

pxlOldLeft = gdImageColorAllocateAlpha(dst, r, g, b, a);

for (i = 0; i < src->sy; i++) {
		pxlSrc = f (src, uCol, i);
		iYPos = i + iOffset;

r = (int)((double)gdImageRed(src,pxlSrc) * dWeight);
		g = (int)((double)gdImageGreen(src,pxlSrc) * dWeight);
		b = (int)((double)gdImageBlue(src,pxlSrc) * dWeight);
		a = (int)((double)gdImageAlpha(src,pxlSrc) * dWeight);

pxlLeft = gdImageColorAllocateAlpha(src, r, g, b, a);

if (pxlLeft == -1) {
			pxlLeft = gdImageColorClosestAlpha(src, r, g, b, a);
		}

if (r>255) {
        		r = 255;
		}

if (g>255) {
			g = 255;
		}

if (b>255) {
    			b = 255;
		}

if (a>127) {
			a = 127;
		}

if (ignoretransparent && pxlSrc == dst->transparent) {
			pxlSrc = dst->transparent;
		} else {
			pxlSrc = gdImageColorAllocateAlpha(dst, r, g, b, a);

if (pxlSrc == -1) {
				pxlSrc = gdImageColorClosestAlpha(dst, r, g, b, a);
			}
		}

if ((iYPos >= 0) && (iYPos < dst->sy)) {
			gdImageSetPixel (dst, uCol, iYPos, pxlSrc);
		}

pxlOldLeft = pxlLeft;
	}

i = iYPos;
	if (i < dst->sy) {
		gdImageSetPixel (dst, uCol, i, pxlLeft);
	}

i--;
	while (++i < dst->sy) {
		gdImageSetPixel (dst, uCol, i, clrBack);
	}
}

/* Rotates an image by 90 degrees (counter clockwise) */
gdImagePtr gdImageRotate90 (gdImagePtr src, int ignoretransparent)
{
	int uY, uX;
	int c,r,g,b,a;
	gdImagePtr dst;
	typedef int (*FuncPtr)(gdImagePtr, int, int);
	FuncPtr f;

if (src->trueColor) {
		f = gdImageGetTrueColorPixel;
	} else {
		f = gdImageGetPixel;
	}
	dst = gdImageCreateTrueColor(src->sy, src->sx);

if (dst != NULL) {
		int old_blendmode = dst->alphaBlendingFlag;
		dst->alphaBlendingFlag = 0;

dst->transparent = src->transparent;

gdImagePaletteCopy (dst, src);

for (uY = 0; uY<src->sy; uY++) {
			for (uX = 0; uX<src->sx; uX++) {
				c = f (src, uX, uY);
				if (!src->trueColor) {
					r = gdImageRed(src,c);
					g = gdImageGreen(src,c);
					b = gdImageBlue(src,c);
					a = gdImageAlpha(src,c);
					c = gdTrueColorAlpha(r, g, b, a);
				}
				if (ignoretransparent && c == dst->transparent) {
					gdImageSetPixel(dst, uY, (dst->sy - uX - 1), dst->transparent);
				} else {
					gdImageSetPixel(dst, uY, (dst->sy - uX - 1), c);
				}
			}
		}
		dst->alphaBlendingFlag = old_blendmode;
	}

return dst;
}

/* Rotates an image by 180 degrees (counter clockwise) */
gdImagePtr gdImageRotate180 (gdImagePtr src, int ignoretransparent)
{
	int uY, uX;
	int c,r,g,b,a;
	gdImagePtr dst;
	typedef int (*FuncPtr)(gdImagePtr, int, int);
	FuncPtr f;

if (src->trueColor) {
		f = gdImageGetTrueColorPixel;
	} else {
		f = gdImageGetPixel;
	}
	dst = gdImageCreateTrueColor(src->sx, src->sy);

if (dst != NULL) {
		int old_blendmode = dst->alphaBlendingFlag;
		dst->alphaBlendingFlag = 0;

dst->transparent = src->transparent;

gdImagePaletteCopy (dst, src);

if (ignoretransparent && c == dst->transparent) {
					gdImageSetPixel(dst, (dst->sx - uX - 1), (dst->sy - uY - 1), dst->transparent);
				} else {
					gdImageSetPixel(dst, (dst->sx - uX - 1), (dst->sy - uY - 1), c);
				}
			}
		}
		dst->alphaBlendingFlag = old_blendmode;
	}

return dst;
}

/* Rotates an image by 270 degrees (counter clockwise) */
gdImagePtr gdImageRotate270 (gdImagePtr src, int ignoretransparent)
{
	int uY, uX;
	int c,r,g,b,a;
	gdImagePtr dst;
	typedef int (*FuncPtr)(gdImagePtr, int, int);
	FuncPtr f;

if (src->trueColor) {
		f = gdImageGetTrueColorPixel;
	} else {
		f = gdImageGetPixel;
	}
	dst = gdImageCreateTrueColor (src->sy, src->sx);

if (dst != NULL) {
		int old_blendmode = dst->alphaBlendingFlag;
		dst->alphaBlendingFlag = 0;

dst->transparent = src->transparent;

gdImagePaletteCopy (dst, src);

if (ignoretransparent && c == dst->transparent) {
					gdImageSetPixel(dst, (dst->sx - uY - 1), uX, dst->transparent);
				} else {
					gdImageSetPixel(dst, (dst->sx - uY - 1), uX, c);
				}
			}
		}
		dst->alphaBlendingFlag = old_blendmode;
	}

return dst;
}

MR SKB